Subversion Repositories

From: Kamil Dudka <kdudka@redhat.com>

Date: Wed, 23 Oct 2013 13:04:22 +0000 (+0200)

Origin: http://repo.or.cz/w/libtar.git/commitdiff/ec613af2e9371d7a3e1f7c7a6822164a4255b4d1

Subject: decode: avoid using a static buffer in th_get_pathname()

decode: avoid using a static buffer in th_get_pathname()

A solution suggested by Chris Frey:

https://lists.feep.net:8080/pipermail/libtar/2013-October/000377.html

Note this can break programs that expect sizeof(TAR) to be fixed.

--- a/lib/decode.c

+++ b/lib/decode.c

@@ -13,6 +13,7 @@

 #include <internal.h>

 #include <stdio.h>

+#include <stdlib.h>

 #include <sys/param.h>

 #include <pwd.h>

 #include <grp.h>

@@ -26,20 +27,30 @@

 char *

 th_get_pathname(TAR *t)

 {

-       static TLS_THREAD char filename[MAXPATHLEN];

-

        if (t->th_buf.gnu_longname)

                return t->th_buf.gnu_longname;

-       if (t->th_buf.prefix[0] != '\0')

+       /* allocate the th_pathname buffer if not already */

+       if (t->th_pathname == NULL)

+       {

+               t->th_pathname = malloc(MAXPATHLEN * sizeof(char));

+               if (t->th_pathname == NULL)

+                       /* out of memory */

+                       return NULL;

+       }

+

+       if (t->th_buf.prefix[0] == '\0')

+       {

+               snprintf(t->th_pathname, MAXPATHLEN, "%.100s", t->th_buf.name);

+       }

+       else

        {

-               snprintf(filename, sizeof(filename), "%.155s/%.100s",

+               snprintf(t->th_pathname, MAXPATHLEN, "%.155s/%.100s",

                         t->th_buf.prefix, t->th_buf.name);

-               return filename;

        }

-       snprintf(filename, sizeof(filename), "%.100s", t->th_buf.name);

-       return filename;

+       /* will be deallocated in tar_close() */

+       return t->th_pathname;

 }

--- a/lib/handle.c

+++ b/lib/handle.c

@@ -121,6 +121,7 @@ tar_close(TAR *t)

                libtar_hash_free(t->h, ((t->oflags & O_ACCMODE) == O_RDONLY

                                        ? free

                                        : (libtar_freefunc_t)tar_dev_free));

+       free(t->th_pathname);

        free(t);

        return i;

--- a/lib/libtar.h

+++ b/lib/libtar.h

@@ -85,6 +85,9 @@ typedef struct

        int options;

        struct tar_header th_buf;

        libtar_hash_t *h;

+

+       /* introduced in libtar 1.2.21 */

+       char *th_pathname;

 }

 TAR;